This invention relates to fuel supply systems for internal combustion engines intended for operation with fuel containing alcohol.
In the German publication "Developments in Automotive Technology and Road Transportation" (Federal Minister for Research and Technology "Motor Vehicles and Road Traffic" Status Seminar 8) by TUV Rheinland GmbH, a fuel supply system for internal combustion engines operating on pure alcohol is disclosed. To solve cold-start problems, that system includes a cold-starting device constructed in the form of a fuel evaporator. Using a so-called cold-start spray, auxiliary or starting fuel is sprayed on heating elements in order to produce a mixture of methanol vapor and air, which then passes through the intake system of the engine into its combustion chambers. Operation of the disclosed cold-starting device requires a certain actuating time, referred to in that publication as the "preheat" time, which depends on the temperature of the engine. The relationship between temperature and the preheat time is such that, with lower and lower temperatures, the preheat time increases linearly.
German Offenlegungsschrift No. 31 37 492 also describes a cold-starting device for an internal combustion engine operating on pure alcohol. The cold-starting device described in that publication automatically switches itself on when a starter switch associated with the engine is actuated if the temperature is below a predetermined value.